1. Field of the Invention
The invention relates to pressure testing storage tanks generally, and more particularly to a method and apparatus that can be used for pressure testing storage tanks that are normally not sealed.
2. Discussion of the Background
Storage tanks in general, and underground storage tanks in particular, are used to store a wide variety of materials. In some applications, the nature of the material dictates that the tank be sealed under normal conditions. In these applications, there are normally governmental requirements for leak testing the tanks. The leak testing is typically accomplished by sealing the tank using the sealing mechanism provided by the tank (and capping off any pipes or connecting fittings installed in the tank), pressurizing the tank, and detecting any escaping air by applying soapy water to the exterior of the tank and looking for bubbles caused by air escaping from the pressurized interior of the tank. 
In other applications, such as wastewater tanks, the storage tanks are not normally sealed. Such tanks typically include an open riser that provides access to the tanks from aboveground. Furthermore, because of nature of the material to be stored in such tanks, there are typically no government requirements to perform leak detection tests on these tanks. However, it is still desirable to ensure that such tanks are watertight even if there are no governmental requirements for leak detection.
What is needed is an inexpensive method and apparatus for leak testing tanks that are not normally sealed.